A method of manufacturing a finished product from a length of a lignocellulosic material, such as a length of solid wood or chip board, includes the steps of impregnating the length of lignocellulosic material through its depth with an impregnating composition consisting of a mineral oil, a non-aqueous solvent for the mineral oil such as dichloromethane or super critical carbon dioxide, and a thermosetting resin and, if necessary, a catalyst therefor dissolved in the mineral oil and solvent. Thereafter, the non-aqueous solvent is removed and the product is subjected to an elevated temperature to polymerise the thermosetting resin to form the finished product.